Where is a definitive guide?

[jborys]

Where can I find a very clear and concise guide with examples on how to write a block, and element, and a modifier. And how each is identified and used?

[Sizart]

Would like this too.
The BEM website gives a good theoretical understanding of the system

[dotnetCarpenter]

I think that https://getbem.com/naming/ gives the most clear and concise explanation but there is still unanswered questions like mixes (https://en.bem.info/methodology/css/#mixes).